1. Field of the Invention
The invention is related to the field of emergency services, and in particular, to a communication network for providing emergency services.
2. Statement of the Problem
In the United States, basic 9-1-1 service is an emergency reporting service where a calling party can dial 9-1-1 in emergency situations. The call is answered at a Public Safety Answering Point (PSAP, also known as a “Public Safety Access Point”). An operator at the PSAP converses with the calling party to determine information on the emergency situation. For instance, the operator may ask the calling party for his/her name, the nature of the emergency, and the location of the emergency, etc. Based on the information gathered by the operator, the operator then contacts emergency personnel to respond to the emergency.
Enhanced 9-1-1 service (E9-1-1) has the added feature of automatically providing the operator with some information on the calling party. For instance, E9-1-1 service includes the added features of Automatic Number Identification (ANI) and Automatic Location Identification (ALI). With Automatic Number Identification (ANI), the operator is automatically provided with telephone number of the phone placing the call for emergency services (e.g., a 9-1-1 call). With Automatic Location Identification (ALI), the PSAP, or another device, queries an ALI database for information on the physical location of the calling party's phone. An ALI database stores records of telephone numbers. A record in the ALI database contains information (such as a street address) on a physical location that corresponds with a telephone number. Responsive to a query from the PSAP, the ALI database returns the location information for the calling party. With the telephone number and the location information, the operator can more effectively handle the emergency call. Other countries have emergency services similar to this.
Traditional communication networks have a rigid architecture for providing emergency services. In a traditional communication network, a PSAP connects to a pair of ALI databases in the emergency services network. A pair of ALI databases is used for redundancy and reliability. The PSAP connects to each ALI database over a dedicated point-to-point connection. The ALI databases are the only resources in the emergency services network that connect with the PSAP and that can serve a request from the PSAP. The PSAP is not able to dynamically connect with other ALI databases or other resources in the emergency services network. The PSAP is unfortunately dependant on the pair of ALI databases to provide information for a 9-1-1 call.
Also, if one of the ALI databases were to be taken out of service for maintenance or upgrades, then the PSAP would be connected to a single ALI database and would become one-sided. If the remaining ALI database was to go out of service, then the PSAP would not be able to adequately service 9-1-1 calls. Emergency services administrators try to avoid architectures that rely on a single device or system because of the higher possibility of a service outage.